Fixes from incorrect rebase

src/lib.rs

@@ -2,13 +2,13 @@
 
 #![feature(asm)]
 #![feature(const_fn)]
-#![feature(associated_consts)]
 #![feature(associated_type_defaults)]
-#![feature(const_fn)]
 #![feature(lang_items)]
 #![feature(panic_handler)]
 #![feature(unwind_attributes)]
 
+#![no_std]
+
 pub use self::register::{Register, RegisterBits, RegisterValue};
 pub use self::pin::{DataDirection, Pin};
 

src/prelude.rs

@@ -1,6 +1,4 @@
 //! Re-exports commonly-used APIs that can be imported at once.
 
-use core::prelude::v1::*;
-
 pub use interrupt::without_interrupts;